Gun control



Dec. 14, 1965 J. A. PAYNEYETAI.

GUN CONTROL 2 Sheets-Sheet 1 Filed May 27,1964

s 5 R0 v, 0 5 5 55% M 2% V .P 7 W .J 2?? LU v! Dec. 14, 1965 J, A; PAYNE ETAL GUN CONTROL Filed May 27, 1964 2 Sheets-Sheet 2 ZAWAf/VCE 1P. GOA/4R0 JAMEJ' A. P4 Y/VE c. 2 WW A 77'ORNE Y5 United States Patent GUN CONTROL James A. Payne, Warren, and Lawrence R. Cunard, Birmingham, Mich., assignors, by direct and mesne assignments, to the United States of America as represented by the Secretary of the Army Filed May 27, 1964, Ser. No. 370,738 Claims. (Cl. 91-448) This invention pertains in general to hydraulic systems used in the control of guns mounted on vehicles and more particularly pertains to hydraulic gun control systems incorporating a pressure differential sensing valve to automatically increase fluid pressure in the system to meet all load requirements encountered in the control of the gun.

Prior art gun control hydraulic systems in vehicles generally utilize a manually operated spool in a control valve to allow fluid pressure to be exerted across a hydraulic motor to traverse the gun. The position of this traversing spool determines the direction and amount of operating pressure oil permitted to flow to the hydraulic motor. The direction in which the operating pressure oil flows to the hydraulic motor determines the direction in which the motor rotates which in turn determines the direction of turret rotation.

These systems include a pressure regulator spool hydraulically connected between an accumulator, which pressurizes the hydraulic oil used in the system, and the control valve. The regulator spool automatically operates to regulate the developed pressure oil in the accumulator to a constant lower operating pressure. Operating pressure oil then passes from the pressure regulating spool to the traversing spool. As indicated above, the available operating pressure oil is then transmitted to a hy draulic motor by the position of the manually operated spool.

These prior art gun control systems have been heretofore satisfactory. However, due to the increased load created by additional armor and heavier guns mounted on modern vehicles, the hydraulic motor has not been able to traverse the gun with the operating oil pressure in all types of terrain. Thus, the motor with regulated or operating pressure is capable of traversing the gun on level terrain, will often stall when the vehicle has been moved to inclined positions. When such stall conditions exist the effectiveness of the vehicle is sharply reduced.

It is therefore an object of the present invention to provide a hydraulic system to meet the differing torque requirements necessary to move a vehicular mounted gun in all types of terrain.

Another object of this invention is to provide a gun control system including a hydraulic motor with means for automatically increasing the fluid pressure across the hydraulic motor when necessary to move and control the gun.

A further object of this invention is to provide a vehicular gun control system incorporating an automatic control valve to eliminate stall conditions of turret mounted guns.

Objects and advantages other than those above set forth will be apparent from the following descriptions when read in connection with the accompanying drawing, in which:

FIG. 1 is a sectional elevation diametrically through a vehicle and its turret showing schematically the power drive for rotating the turret.

FIG. 2 is a schematic view and not to scale showing the hydraulic system for controlling rate and direction of rotation of a hydraulic motor together with an automatic sensing valve to permit full accumulator pressure to appear across the motor.

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FIG. 3 is a side view, partly in cross section, of the regulator override schematically illustrated in FIG. 2.

Referring in detail to the drawings, FIG. 1 shows a vehicle body 1, having a large internal ring gear 2 rigidly fixed therein. A turret 3 is rotatably mounted on the body by means of supports 4 carried by support ring 5. This support ring is rotatably mounted on the ring gear by anti-friction bearings 6. A shaft 7 is journaled on the support ring by any suitable bearing means (not shown). At its lower end, the shaft carries a fixed pinion 8 in mesh With the ring gear 2 and has at its upper end a gear 9 meshing with a pinion 10. The pinion 10 is fixed to the output shaft of a reversible hydraulic motor 1. By this construction rotation of the motor effects rotation of the turret 3 to traverse gun 12 to the left or right depending on direction of motor rotation. Trunnions 13 on the gun 12 pivot the gun in the turret for elevation of the gun by any suitable power source.

The hydraulic motor may be any suitable reversible motor such as the radial piston type shown and described in U.S. Patent No. 2,406,138 to W. Ferris et al. To operate this motor and traverse the gun a. hydraulic gun control system is employed.

As illustrated in FIG. 2, this hydraulic system includes a source of fluid pressure provided by accumulator 15. The accumulator is connected by suitable fluid conducting tubing 17 to passage or opening 19 formed in sleeve 20 fixed in valve body assembly 21 which in turn is fixed in the turret 3. This opening leads into a chamber 23 formed in the sleeve. Regulator spool 25 is reciprocally mounted in this chamber and is formed with land 27 which controls the passage of fluid into the regulator spool chamber through passage 19. Also formed on the spool is an enlarged cylindrical portion 28 which conforms to the interior dimensions of the regulator spool chamber and forms a support for spring seat 29. This portion also prevents the passage of hydraulic fluid into the cavity 31 formed in the valve assembly. Mounted in cavity 31 is dual spring 33 which exerts a force on the spring seat and the regulator spool to tend to fully open the passage 19 to permit full accumulator pressure into the chamber 23. Opposing this force is a second force provided by spring 35, mounted in the valve assembly contacting the end 26 of the regulator spool, which tends to close the passage 19 and reduce the pressure in chamber 23. By selecting spring strengths the land 27 can be made to partially close the passage 19 to regulate the pressure in chamber 23. Thus, if the accumulator pressure is in the desired 1225 :50 p.s.i. range, the regulator can for example be made to reduce and regulate the pressure available to chamber 23 to 950:50 p.s.i.

A housing 37 is provided on the valve body assembly near one end of regulator spool 25. A reciprocally movable piston 39 is mounted in this housing for a purpose to be described below. This piston is formed with an extension or rod which projects through an end wall 43 provided on the valve assembly and is adapted to contact the extension 45 integrally formed on the regulator spool.

FIG. 3 illustrates a practical form of piston and its housing attached to the valve body assembly. In this form, housing 37 is secured to the assembly by threaded bolts 36. A wall 38 formed on one end of the housing provides a seat for the dual spring 33 and provides a cover for spring cavity 31. A hollow adapter 30 is threadedly connected to the other end of the housing and is formed with a seat 32 for the reception of a fluid conducting tube. A conventional tube coupling such as that shown in U.S. Patent No. 2,139,413 to H. Kreidel may be used to connect such a tube to the adapter 39. As shown, the piston 39 divides the housing into separate chambers 40 and 42 and has the extension 41 extending through a suitable opening in end wall 38. This extension is adapted to contact and displace the regulator spool 25 overriding the retarding force of spring 35 when chamber 40 is sutficiently pressurized.

The regulator spool chamber 23 is hydraulically connected to a second chamber 47 formed in the valve body assembly by a suitable conduit or passage 49 in the body assembly. In this second chamber a reciprocally movable traversing spool 58 is mounted. As shown in FIG. 2, suitable springs 51 and 53 mounted in cavity 50 center the spool in the chamber. This spool is formed with lands 57 and 59 which completely block the orifices 82 and 80 for passages 61 and .63 also formed in the body assembly when the spool is centered by the centering springs.

Passage 63 leads to chamber 74 formed in the valve body assembly and then to a conduit 65 which is connected to one side of the reversible hydraulic motor. Passage 61 leads to chamber 76 and then to conduit 67 extending to the other side of the hydraulic motor. 7

By manually displacing the traversing spool by handle 69 toward the operator, passage 63, leading to one side of the motor, is opened to regulator pressure by movement of land 59 to the right. In this spool position land 57 has also been moved to the right to prevent the regulator pressure from reaching passage 61 leading to the other side of the motor. However, by this movement of land 57, passage 61 and orifice 82 have been opened into chamber 62 which in turn is connected to spring cavity 50 by passages 64 and 66 and orifices 68 formed in the traverse spool 58. A fluid return line 52 connects the cavity 50 to a fluid reservoir 54.

In the above described spool position a fluid pressure differential appears across the motor and causes the motor 11 to turn counter-clockwise, pinion 8 geared to the motor then traverses the turret to the left. Fluid expelled by the motor returns to the reservoir through the return line 52 by way of conduit 67 and passages 61, 64, 66 and cavity 50.

By moving the spool in the opposite direction away from the operator, land 57 opens passage 61 to regulated operating pressure while land 59 prevents this pressure from reaching passage 63. This reverses the flow of fluld through the hydraulic motor and results in the counterclockwise movement of the motor to traverse the turret to the right. When so traversed, fluid expelled by the motor returns to the reservoir 54 through conduit 65, cav- -ity 74, passage 63, passages 60 and 66 in the. traverse spool, chamber 50 and return pipe 52, respectively.

Motor speed and torque are controlled by controlling the opening of orifices 80 and 82 by conventional flats formed on the lands 57 and 59.

With the hydraulic control system described above the gun can be efiiciently and accurately controlled. However, when the vehicle on which the gun is mounted moves from horizontal to inclined positions, a greater load is placed on the motor by the inclined turret and attempts to traverse the turret would probably fail. This turret stall condition reduces the effectiveness of armored vehicles since the full potential of the vehicle cannot be realized.

Such stall conditions can be eliminated or substantially reduced by applying a greater pressure across the motor to produce a greater motor torque to move the increased load.

To permit full accumulator pressure to be applied across the motor, an automatic pressure sensing valve is placed in parallel with the motor. This valve is formed by a spool 72 which is reciprocally mounted in a chamber 71 formed in the valve body assembly. Biasing springs 73 and 75 in cavities 74 and 76 are mounted on spring seats 77 and 79 and center the spool in the chamber. As shown in FIG. 2, these cavities are hydraulically connected to passages 61 and 63 and conduits 65 and 67. The spool is formed with lands 81 and 83 which control orifices 85 and 87 for conduit or tube .89 wh ch leads into the'chamber 71. The spool 72 is further formed with enlarged bearing portions 91 and 93 substantially conforming to the internal dimensions of chamber 71.

A passage 95 leads from the traverse spool chamber 47 to the chamber 71 between lands 81 and 83 and allows the hydraulic fluid to reach chamber 71. Conduit 89 leading from spaced orifices 85 and 87 in this chamber extends to chamber 40 in the housing 37 behind the piston 39 in order that the piston may be actuated by hydraulic fluid coming from chamber 71.

When a predetermined pressure differential appears across the motor (for example, 400 p.s.i.) the spool 72, due to the differential pressure in the spring cavities 74 and 76, will automatically move to the left or right to open either orifice 85 or 87 depending on the direction of displacement of the traverse spool 58.

The above mentioned pressure differential is the result of the additional loads placed on the motor. When the vehicle has been moved from a level to an inclined surface and turret traversal is desired, the traverse spool is displaced in the appropriate direction. Since an additional torque load is placed on the motor, the motor will momentarily tend to slow down. Pressure will then quickly build up in one of the spring chambers 74 or 76 and will exert a force on spool face 84 or 86. When a predetermined pressure differential is reached, the spring 73 or 75 will be overcome and the spool 72 will be appropriately shifted. Since the orifice 85 or 87 is opened, by this spool displacement regulator pressure enters line 89 from chamber 71; line 89 is connected to the housing 37 behind piston 39. This pressure forces the piston 39 to the left, and piston rod 41 will contact spool extension 45. The force on extension 45 overcomes the retarding force of spring 35, and the regulator spool will be moved to a position whereby land 27 is completely removed from the opening 19, and full accumulator pressure is allowed into the system through the regulator chamber 23.

Thus, if the traverse spool 69 has been moved toward the operator to traverse left and the pressure sensing spool 72 has been displaced to the left when a predetermined pressure differential has been reached, the regulator spool shifts to the left completely opening passage 19. Chamber 23 then experiences full accumulator pressure. Since passage 63 has been opened by land 59 full accumulator pressure is available to motor 11 to increase the torque thereof and move the increased load.

When the pressure differential in chambers 74 and 76 drops below the predetermined amount, springs 73 and 75 again center the automatic valve spool 72. When so centered, piston 39 will not exert any substantial force on regulator spool 25 and that spool is centered by springs 33 and 35 to its original position, and land 27 partially closes opening 19 to reduce the pressure in chamber 23. Motor 11 then operates on the regulated pressure and bleed lines such as 97 and 99 return excess fluid to the reservoir 54.

The hydraulic pressure to power the system is derived from the vehicle batteries (not shown) which run electric drive motor 103 that is coupled to a gear pump 101 submerged in reservoir 54 for the hydraulic oil. As the gear pump is operated, it forces oil from the reservoir through a ball check valve and filter 105 into the accumulator 15 through tubing 17 and 18. The accumulator houses a floating piston, the top side of which is precharged with a suitable gas to about 525 p.s.i. As oil is pumped into the accumulator, it acts on the floating piston and compresses the gas until the oil pressure reaches a predetermined pressure, for example 1,225 p.s.i. At this point, a pressure switch which is activated by the developed oil pressure in the accumulator opens and breaks an electrical connection (not shown) to a motor relay to shut off the electric drive motor and the gear pump. When the stored hydraulic pressure in the accumulator is depleted to a predetermined lower pressure, for example 925 p.s.i., the pressure switch closes restoring the electrical connection to the motor relay and causes the electric motor to start and the gear pump to operate until the accumulator is recharged to the higher predetermined pressure.

By the structure described above, the hydraulic motor 11 will be able to move all loads in spite of varying terrain and resulting increased loads. With this system re quirements for larger motors and amounts of hydraulic fluids are eliminated.

It is to be understood that the invention is not limited to the details of the illustrative embodiments particularly described herein but that various modifications may be made without departing from the invention as defined in the claims.

What is claimed is:

1. In a hydraulic system for controlling a rotatable hydraulic motor to move a load, the combination of a source of fluid pressure, a valve assembly hydraulically connected to said source of fluid pressure, a regulator valve, a motor control valve and a pressure sensing valve mounted in said assembly, said regulator valve being spring centered in said assembly to reduce the pressure in said assembly available from said source of fluid pressure, said pressure sensing valve being spring centered in said assembly having opposite ends exposed to fluid pressure differentials in said system, said pressure sensing valve being adapted to be moved longitudinally by predetermined unequal forces exerted by fluid pressure in said system when a predetermined pressure diflerential appears across said sensing valve, a housing secured to said valve assembly adjacent said regulator valve, a piston mounted in said housing adapted to contact and displace said regulator valve so that full source pressure is allowed in said assembly, a conduit connecting said housing with said regulator valve, said piston being adapted to displace said regulator valve to admit full source pressure in said assembly when a predetermined pressure differential appears across said pressure sensing valve.

2. In a hydraulic system, the combination of a reversible, rotatable hydraulic motor, a source of substantially constant fluid pressure, a valve assembly for controlling the flow of fluid from the source to the motor, said valve assembly being formed by a valve housing having first, second and third separate valve chambers formed therein, a regulator spool mounted in said first chamber adapted to control the fluid pressure available to said valve assembly from said source, a second spool mounted in said second chamber and a third spool mounted in said third chamber, a first fluid conducting means in said assembly connecting said first chamber to said second chamber, second and third fluid conducting means connecting said second chamber to opposite sides of said motor and to opposite ends of said third spool, a fourth fluid conducting means connecting said second chamber to said third chamber, piston means mounted adjacent said first chamber adapted to displace said regulator spool to allow full system pressure into the first and second chambers, a housing for said piston means, fifth fluid conducting means connecting said third chamber to said piston housing, said fifth fluid conducting means being open to pressure from said assembly by displacement of said third spool in said third chamber when a predetermined pressure differential is experienced by the ends of said third spool.

3. The system defined in claim 2 wherein said spools are spring centered in said chambers and wherein said second spool is adapted to control the direction of motor rotation by control of direction of fluid flow to said motor.

4. The system defined in claim 3 wherein said fifth fluid conducting means is connected to said third chamber by spaced orifices, and wherein said third spool is formed with spaced lands blocking entry of fluid into said fifth fluid conducting means when said third spool is centered in said third chamber.

5. In a gun control system which incorporates a reversible hydraulic motor, a fluid pressure source, a valve assembly having first second and third valve chambers each with a spool reciprocally mounted therein, a piston mounted adjacent said first chamber, fluid conducting means connecting said source to said first chamber, said first spool being adapted to reduce the pressure in said first chamber from said source, second fluid conducting means connecting said first chamber to said second chamber, spaced third and fourth fluid conducting means connecting said second chamber to opposite ends of said third spool and to opposite sides of said motor, said second spool having lands for controlling the passage of fluid from said second chamber to and from said motor, a fifth fluid conducting means connecting said second chamber to said third chamber, a sixth fluid conducting means connecting spaced orifices in said third chamber to said piston, said third spool having spaced lands formed thereon normally preventing passage of fluid from said third chamber to said piston, said third spool being adapted to be displaced by a predetermined pressure differential across said third spool to allow fluid pressure to reach said piston, said piston being adapted to displace said first spool to allow substantially full source pressure to reach said first and second chambers.

6. The structure defined in claim 5 wherein the opposite ends of said third spool are equal in area and provide surfaces to experience the pressure diflerentials appearing across said third spool and said motor.

7. In a hydraulic system for controlling a hydraulic motor, the combination of a source of fluid pressure and a valve assembly comprising a pressure regulator valve, 21 motor control valve for controlling the direction of movement of said motor, a single pressure sensing valve actuated in response to a change in pressure differential between said pressure regulator valve and. said motor regardless of the direction of motor movement, means for adjusting said pressure regulator valve to control the pressure applied to said motor, and means for transferring hydraulic fluid between said pressure sensing valve and said adjusting means upon actuation of said pressure sensing valve.

8. The hydraulic system of claim 7 in which adjusting means includes a piston.

9. The hydraulic system of claim 7 wherein said means for adjusting said pressure regulator valve includes a piston within a housing attached to the body of said valve assembly.

10. The hydraulic system of claim 7 wherein the motor is a reversible hydraulic motor.

References Cited by the Examiner UNITED STATES PATENTS 1,067,233 7/1913 Adams 9l448 X 2,408,303 9/1946 Ernst 60-52 2,892,312 6/1959 Allen 60-52 2,900,960 8/1959 Gratzmuller 91-448 X SAMUEL LEVINE, Primary Examiner. 

1. IN A HYDRAULIC SYSTEM FOR CONTROLLING A ROTATABLE HYDRAULIC MOTOR TO MOVE A LOAD, THE COMBINATION OF A SOURCE OF FLUID PRESSURE, A VALVE ASSEMBLY HYDRAULICALLY CONNECTED TO SAID SOURCE OF FLUID PRESSURE, A REGULATOR VALVE, A MOTOR CONTROL VALVE AND A PRESSURE SENSING VALVE MOUNTED IN SAID ASSEMBLY, SAID REGULATOR VALVE BEING SPRING CENTERED IN SAID ASSEMBLY TO REDUCE THE PRESSURE IN SAID ASSEMBLY AVAILABLE FROM SAID SOURCE OF FLUID PRESSURE, SAID PRESSURE SENSING VALVE BEING SPRING CENTERED IN SAID ASSEMBLY HAVING OPPOSITE ENDS EXPOSED TO FLUID PRESSURE DIFFERENTIALS IN SAID SYSTEM, SAID PRESSURE SENSING VALVE BEING ADAPTED TO BE MOVED LONGITUDINALLY BY PREDETERMINED UNEQUAL FORCES EXERTED BY FLUID PRESSURE IN SAID SYSTEM WHEN A PREDETERMINED PRESSURE DIFFERENTIAL APPEARS ACROSS SAID SENSING VALVE, A HOUSING SECURED TO SAID VALVE ASSEMBLY ADJACENT SAID REGULATOR VALVE, A PISTON MOUNTED IN SAID HOUSING ADAPTED TO CONTACT AND DISPLACE SAID REGULATOR VALVE SO THAT FULL SOURCE PRESSURE IS ALLOWED IN SAID ASSEMBLY, A CONDUIT CONNECTING SAID HOUSING WITH SAID REGULATOR VALVE, SAID PISTON BEING ADAPTED TO DISPLACE SAID REGULATOR VALVE TO ADMIT FULL SOURCE PRESSURE IN SAID ASSEMBLY WHEN A PREDETERMINED PRESSURE DIFFERENTIAL APPEARS ACROSS SAID PRESSURE SENSING VALVE. 